At present, in order to center the rollers at the foot of an ingot mold, the operator carries out a series of manual operations for adjusting the roller position using a monolithic template designed to be adapted and fixed with shims or spacers to the inner walls of the crystallizer, accommodated inside the ingot mold body, so as to follow the tapers present in the crystallizer walls.
The above manual centering operations, using such a monolithic template, disadvantageously require long times and a good centering is in any case highly depending on the operators' experience and skills.
As an alternative, a centering template may be used which consists of multiple longitudinal elements separate from one another, such as for example that described in document EP2334453. Said longitudinal elements have an outer surface having a shape complementary to respective inner wall portions of the crystallizer, and at least one air chamber is provided, which is accommodated into the template and is adapted to expand so as to adhere the longitudinal elements to the respective inner wall portions of the crystallizer. Such a template is particularly effective for quadrangular section crystallizers and allows a quick and accurate centering of the rollers irrespective of the operators' skills and experience, ensuring the repeatability of the operation of centering. However, disadvantageously, in the case of a round section crystallizer, such a template is not accurate since in this case the edges that characterize a square or rectangular section of the crystallizer against which the longitudinal elements rests, taking on a unique position, are not provided. In the case of round ingot mold, the template described in EP2334453 includes longitudinal elements having an outer surface with a shape substantially complementary to respective inner wall portions of the crystallizer and having a circle arc cross section, but being able to rest each time on different points of the inner surface of the crystallizer. The positioning variability of the longitudinal elements of the template causes inaccuracy in aligning the rollers at the foot, which is thus subject to an error whenever the operation is carried out.
The need of providing a template for centering rollers at the foot of an ingot mold, suitable for casting round section products, which allows the above drawbacks to be overcome, is therefore felt.